imac G5 blank screen

[eyesubmit]

Hiya all. I am new to this forum so hi to all who post/read this forum.
I have an imac G5 with a blank screen so changed the backlight inverter to no avail. I replaced the original inverter and reset the PRAM and after the 2 or 3 gongs got it working but the screen froze after a min or two. I turned of the computer and was back to square one.... blank screen. I can only get it to come on by resetting the pram each time??? some times i get the computer to the start screen sometimes it will freeze at the spinning cogs stage. Any help or advise would be appreciated. Thanks.

 

[MTI]

Which G5 iMac (screen size, processor speed, year build, etc.)? It may help to know what generation machine it is.

Before replacing the inverter board, were you able to confirm that the LCD was functioning (see the graphics with a bright light, etc.)?

 

[eyesubmit]

The G5 is a 17" screen 1.8 model number CK 531 H0LSDX is the serial number. I checked with a bright light and yes could see the computer working. Not sure what to check next? Any ideas? Please be aware i am not that great on computers so any advice would be welcome.

 

[MTI]

If the inverter was replaced by a known good one, then the "diagnostic tree" for your unlit screen is either the 1) the power supply; 2) the connector cables from the inverter board or 3) the florescent tube that illuminates the LCD itself.

The issue you're having with the PRAM setting and the machine actually illuminating the screen would tend to rule out the cables or bulb, which then focuses the issue on the the power supply. If the bulb or cables were compromised, then it shouldn't light up.

G5 iMac power supplies have a known history of higher than average failure history. The output voltages of the power supply can be checked by a tech or DIY if you're handy with a voltmeter and have the tech specs available as a guide.

 

[BlizzardBomb]

The G5 is a 17" screen 1.8 model number CK 531 H0LSDX is the serial number. I checked with a bright light and yes could see the computer working. Not sure what to check next? Any ideas? Please be aware i am not that great on computers so any advice would be welcome.

Likely to be the logic board. I self-diagnosed my own iMac when it would turn on but fans were super loud (with no picture). The LED inside was lit indicating inverter/ display failure I think. But when taken to the Apple Store for repair, replacing both the inverter and display did nothing and a new logic board was the only fix.